OSLO, Norway --A Norwegian teenager has been cleared of DVD piracy charges in a landmark trial brought by major Hollywood studios.

The Oslo court said Jon Johansen, known in Norway as "DVD Jon," had not broken the law when he helped unlock a code and distribute a computer program enabling DVD films to be copied.

"Johansen is found not guilty," Judge Irene Sogn told the court. She said prosecutors could appeal against the unanimous verdict.

Johansen said after the ruling that he would celebrate by "watching DVD films on unlicensed players."

Prosecutors had asked for a 90-day suspended jail term for Johansen, 19, who developed the program when he was 15.

The teenager has become a symbol for hackers worldwide who say making software such as Johansen's -- called DeCSS -- is an act of intellectual freedom rather than theft.

DeCSS defeats the copyright protection system known as Contents Scramble System (CSS), which the entertainment industry uses to protect films distributed on DVDs.

Johansen created and published DeCSS so that he would be able to view DVDs on his Linux computer. He said the program meant the film industry no longer had a monopoly on making DVD players.

The prosecution was brought after a complaint was filed by the Motion Picture Association (MPA), which represents the major Hollywood studios.

The studios argued unauthorised copying was copyright theft and undermined a market for DVDs and videos worth $20 billion a year in North America alone.

But Johansen argued his code was necessary to watch movies he already owned, on his Linux-based computer, for which DVD software had not yet been written.

He said since he owned the DVDs, he should be able to view them as he liked, preferably on his own computer. The court, citing consumer laws which protect consumers' fair use of their own property, agreed.

The court ruled there was "no evidence" that Johansen or others used the decryption code called DeCSS for illegal purposes. Nor was there any evidence that Johansen intended to contribute to illegal copying.

The court also ruled that it is not illegal to use the DeCSS code to watch DVD films obtained by legal means.

In the United States, Johansen's case raised concerns among Internet users of what they see as a constitutional right to freedom of expression. A battle is raging in the U.S. over a 1998 copyright law that bans software like DeCSS.

Even though Johansen's software is now outdated, it was the first to give the so-called source codes, or instructions, for how to decipher DVD codes.